Introduction Flashcards
What is ASP.NET Core?
ASP.NET Core is Microsoft’s web development platform.
What does ASP.NET Core consist of?
ASP.NET Core consists of a platform, a series of principal frameworks for creating applications, and secondary utility frameworks that provide supporting features.
What does the ASP.NET Core platform do?
Processes HTTP requests
What does the application framework consist of?
MVC Framework, Razor Pages and Blazor.
These frameworks are complementary and solve different problems, or, for some features, solve the same problems in different ways.
What does the (Secondary) Utility Framework consist of?
Identity and entidy framework
What does the platform consist of?
HTTP Server, Middleware, URL routing, Dependency Injection, Configuration and Logging, Caching, Model Binding, Razor, gRPC, SignalR
What is the MVC Framework?
The MVC Framework was introduced in the pre-Core days of ASP.NET. The original ASP.NET relied on a development model called Web Pages, which re-created the experience of writing desktop applications but resulted in unwieldy web projects that did not scale well. The MVC Framework was introduced alongside Web Pages with a development model that embraced the character of HTTP and HTML, rather than trying to hide it.
MVC stands for Model-View-Controller, which is a design pattern that describes the shape of an application. The MVC pattern emphasizes separation of concerns, where areas of functionality are defined independently, which was an effective antidote to the indistinct architectures that Web Pages led to.
Early versions of the MVC Framework were built on the ASP.NET foundations that were originally designed for Web Pages, which led to some awkward features and workarounds. With the move to .NET Core, ASP.NET became ASP.NET Core, and the MVC Framework was rebuilt on an open, extensible, and cross-platform foundation.
The MVC Framework remains an important part of ASP.NET Core, but the way it is commonly used has changed with the rise of single-page applications (SPAs). In an SPA, the browser makes a single HTTP request and receives an HTML document that delivers a rich client, typically written in a JavaScript client such as Angular or React. The shift to SPAs means that the clean separation that the MVC Framework was originally intended for is not as important, and the emphasis placed on following the MVC pattern is no longer essential, even though the MVC Framework remains useful (and is used to support SPAs through web services, as described in Chapter 19).
What is Razor pages?
One drawback of the MVC Framework is that it can require a lot of preparatory work before an application can start producing content. Despite its structural problems, one advantage of Web Pages was that simple applications could be created in a couple of hours.
Razor Pages takes the development ethos of Web Pages and implements it using the platform features originally developed for the MVC Framework. Code and content are mixed to form self-contained pages; this re-creates the speed of Web Pages development without some of the underlying technical problems (although the issue of scaling up complex projects can still be an issue).
Razor Pages can be used alongside the MVC Framework, which is how I tend to use them. I write the main parts of the application using the MVC Framework and use Razor Pages for the secondary features, such as administration and reporting tools. You can see this approach in Chapters 7–11, where I develop a realistic ASP.NET Core application called SportsStore.
What is blazor?
The rise of JavaScript client-side frameworks can be a barrier for C# developers, who must learn a different—and somewhat idiosyncratic—programming language. I have come to love JavaScript, which is as fluid and expressive as C#. But it takes time and commitment to become proficient in a new programming language, especially one that has fundamental differences from C#.
Blazor attempts to bridge this gap by allowing C# to be used to write client-side applications. There are two versions of Blazor: Blazor Server and Blazor WebAssembly. Blazor Server is a stable and supported part of ASP.NET Core, and it works by using a persistent HTTP connection to the ASP.NET Core server, where the application’s C# code is executed. Blazor WebAssembly is an experimental release that goes one step further and executes the application’s C# code in the browser. Neither version of Blazor is suited for all situations, as I explain in Chapter 33, but they both give a sense of direction for the future of ASP.NET Core development.
What is utility frameworks?
Two frameworks are closely associated with ASP.NET Core but are not used directly to generate HTML content or data. Entity Framework Core is Microsoft’s object-relational mapping (ORM) framework, which represents data stored in a relational database as .NET objects. Entity Framework Core can be used in any .NET Core application, and it is commonly used to access databases in ASP.NET Core applications.
ASP.NET Core Identity is Microsoft’s authentication and authorization framework, and it is used to validate user credentials in ASP.NET Core applications and restrict access to application features.
I describe only the basic features of both frameworks in this book, focusing on the capabilities required by most ASP.NET Core applications. But these are both complex frameworks that are too large to describe in detail in what is already a large book about ASP.NET Core.
What is the ASP.NET Core Platform?
The ASP.NET Core platform contains the low-level features required to receive and process HTTP requests and create responses. There is an integrated HTTP server, a system of middleware components to handle requests, and core features that the application frameworks depend on, such as URL routing and the Razor view engine.
Most of your development time will be spent with the application frameworks, but effective ASP.NET Core use requires an understanding of the powerful capabilities that the platform provides, without which the higher-level frameworks could not function. I demonstrate how the ASP.NET Core platform works in detail in Part 2 of this book and explain how the features it provides underpin every aspect of ASP.NET Core development.
I have not described two notable platform features in this book: SignalR and gRPC. SignalR is used to create low-latency communication channels between applications. It provides the foundation for the Blazor Server framework that I describe in Part 4 of this book, but SignalR is rarely used directly, and there are better alternatives for those few projects that need low-latency messaging, such as Azure Event Grid or Azure Service Bus.
gRPC is an emerging standard for cross-platform remote procedure calls (RPCs) over HTTP that was originally created by Google (the g in gRPC) and offers efficiency and scalability benefits. gRPC may be the future standard for web services, but it cannot be used in web applications because it requires low-level control of the HTTP messages that it sends, which browsers do not allow. (There is a browser library that allows gRPC to be used via a proxy server, but that undermines the benefits of using gRPC.) Until gRPC can be used in the browser, its inclusion in ASP.NET Core is of interest only for projects that use it for communication between back-end servers, for which many alternative protocols exist. I may cover gRPC in future editions of this book but not until it can be used in the browser or becomes the dominant data-center protocol.
